This is probably about the fact that red phosphorus (required for the original process) cannot be purchased without a license (https://nitter.net/andrewmccalip/

This is probably about the fact that red phosphorus (required for the original process) cannot be purchased without a license (https://nitter.net/andrewmccalip/status/1684191067477004288#m https://nitter.net/andrewmccalip/status/1684191067477004288#...), so kitchen chemists are out of the race. Established labs should have less problems though.